/**
 ******************************************************************************
 * @addtogroup PIOS PIOS Core hardware abstraction layer
 * @{
 * @addtogroup   PIOS_USB_HID USB COM Functions
 * @brief PIOS USB COM implementation for HID interfaces
 * @notes      This implements serial emulation over HID reports
 * @{
 *
 * @file       pios_usb_hid.c
 * @author     The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
 * @brief      USB COM functions (STM32 dependent code)
 * @see        The GNU Public License (GPL) Version 3
 *
 *****************************************************************************/
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */

#include "pios.h"

#ifdef PIOS_INCLUDE_USB_HID

#include "pios_usb_hid_priv.h"
#include "pios_usb_board_data.h" /* PIOS_BOARD_*_DATA_LENGTH */

/* STM32 USB Library Definitions */
#include "usb_lib.h"

static void PIOS_USB_HID_RegisterTxCallback(uint32_t usbhid_id, pios_com_callback tx_out_cb, uint32_t context);
static void PIOS_USB_HID_RegisterRxCallback(uint32_t usbhid_id, pios_com_callback rx_in_cb, uint32_t context);
static void PIOS_USB_HID_TxStart(uint32_t usbhid_id, uint16_t tx_bytes_avail);
static void PIOS_USB_HID_RxStart(uint32_t usbhid_id, uint16_t rx_bytes_avail);

const struct pios_com_driver pios_usb_hid_com_driver = {
    .tx_start   = PIOS_USB_HID_TxStart,
    .rx_start   = PIOS_USB_HID_RxStart,
    .bind_tx_cb = PIOS_USB_HID_RegisterTxCallback,
    .bind_rx_cb = PIOS_USB_HID_RegisterRxCallback,
    .available  = PIOS_USB_CheckAvailable,
};

enum pios_usb_hid_dev_magic {
    PIOS_USB_HID_DEV_MAGIC = 0xAA00BB00,
};

struct pios_usb_hid_dev {
    enum pios_usb_hid_dev_magic   magic;
    const struct pios_usb_hid_cfg *cfg;

    uint32_t lower_id;

    pios_com_callback rx_in_cb;
    uint32_t rx_in_context;
    pios_com_callback tx_out_cb;
    uint32_t tx_out_context;

    uint8_t  rx_packet_buffer[PIOS_USB_BOARD_HID_DATA_LENGTH];
    uint8_t  tx_packet_buffer[PIOS_USB_BOARD_HID_DATA_LENGTH];

    uint32_t rx_dropped;
    uint32_t rx_oversize;
};

static bool PIOS_USB_HID_validate(struct pios_usb_hid_dev *usb_hid_dev)
{
    return usb_hid_dev->magic == PIOS_USB_HID_DEV_MAGIC;
}

#ifdef PIOS_INCLUDE_FREERTOS
static struct pios_usb_hid_dev *PIOS_USB_HID_alloc(void)
{
    struct pios_usb_hid_dev *usb_hid_dev;

    usb_hid_dev = (struct pios_usb_hid_dev *)pios_malloc(sizeof(struct pios_usb_hid_dev));
    if (!usb_hid_dev) {
        return NULL;
    }

    memset(usb_hid_dev, 0, sizeof(struct pios_usb_hid_dev));
    usb_hid_dev->magic = PIOS_USB_HID_DEV_MAGIC;
    return usb_hid_dev;
}
#else
static struct pios_usb_hid_dev pios_usb_hid_devs[PIOS_USB_HID_MAX_DEVS];
static uint8_t pios_usb_hid_num_devs;
static struct pios_usb_hid_dev *PIOS_USB_HID_alloc(void)
{
    struct pios_usb_hid_dev *usb_hid_dev;

    if (pios_usb_hid_num_devs >= PIOS_USB_HID_MAX_DEVS) {
        return NULL;
    }

    usb_hid_dev = &pios_usb_hid_devs[pios_usb_hid_num_devs++];

    memset(usb_hid_dev, 0, sizeof(struct pios_usb_hid_dev));
    usb_hid_dev->magic = PIOS_USB_HID_DEV_MAGIC;

    return usb_hid_dev;
}
#endif /* ifdef PIOS_INCLUDE_FREERTOS */

static void PIOS_USB_HID_EP_IN_Callback(void);
static void PIOS_USB_HID_EP_OUT_Callback(void);

static uint32_t pios_usb_hid_id;

/* Need a better way to pull these in */
extern void(*pEpInt_IN[7]) (void);
extern void(*pEpInt_OUT[7]) (void);

int32_t PIOS_USB_HID_Init(uint32_t *usbhid_id, const struct pios_usb_hid_cfg *cfg, uint32_t lower_id)
{
    PIOS_Assert(usbhid_id);
    PIOS_Assert(cfg);

    struct pios_usb_hid_dev *usb_hid_dev;

    usb_hid_dev = (struct pios_usb_hid_dev *)PIOS_USB_HID_alloc();
    if (!usb_hid_dev) {
        goto out_fail;
    }

    /* Bind the configuration to the device instance */
    usb_hid_dev->cfg = cfg;
    usb_hid_dev->lower_id = lower_id;

    pios_usb_hid_id  = (uint32_t)usb_hid_dev;

    /* Bind lower level callbacks into the USB infrastructure */
    pEpInt_IN[cfg->data_tx_ep - 1]  = PIOS_USB_HID_EP_IN_Callback;
    pEpInt_OUT[cfg->data_rx_ep - 1] = PIOS_USB_HID_EP_OUT_Callback;

    *usbhid_id = (uint32_t)usb_hid_dev;

    return 0;

out_fail:
    return -1;
}


static void PIOS_USB_HID_SendReport(struct pios_usb_hid_dev *usb_hid_dev)
{
    uint16_t bytes_to_tx;

    if (!usb_hid_dev->tx_out_cb) {
        return;
    }

    bool need_yield = false;
#ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
    bytes_to_tx = (usb_hid_dev->tx_out_cb)(usb_hid_dev->tx_out_context,
                                           &usb_hid_dev->tx_packet_buffer[1],
                                           sizeof(usb_hid_dev->tx_packet_buffer) - 1,
                                           NULL,
                                           &need_yield);
#else
    bytes_to_tx = (usb_hid_dev->tx_out_cb)(usb_hid_dev->tx_out_context,
                                           &usb_hid_dev->tx_packet_buffer[2],
                                           sizeof(usb_hid_dev->tx_packet_buffer) - 2,
                                           NULL,
                                           &need_yield);
#endif
    if (bytes_to_tx == 0) {
        return;
    }

    /* Always set type as report ID */
    usb_hid_dev->tx_packet_buffer[0] = 1;

#ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
    UserToPMABufferCopy(usb_hid_dev->tx_packet_buffer,
                        GetEPTxAddr(usb_hid_dev->cfg->data_tx_ep),
                        bytes_to_tx + 1);
#else
    usb_hid_dev->tx_packet_buffer[1] = bytes_to_tx;
    UserToPMABufferCopy(usb_hid_dev->tx_packet_buffer,
                        GetEPTxAddr(usb_hid_dev->cfg->data_tx_ep),
                        bytes_to_tx + 2);
#endif
    /* Is this correct?  Why do we always send the whole buffer? */
    SetEPTxCount(usb_hid_dev->cfg->data_tx_ep, sizeof(usb_hid_dev->tx_packet_buffer));
    SetEPTxValid(usb_hid_dev->cfg->data_tx_ep);

#ifdef PIOS_INCLUDE_FREERTOS
    if (need_yield) {
        vPortYield();
    }
#endif /* PIOS_INCLUDE_FREERTOS */
}

static void PIOS_USB_HID_RxStart(uint32_t usbhid_id, uint16_t rx_bytes_avail)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)usbhid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    if (!PIOS_USB_CheckAvailable(usb_hid_dev->lower_id)) {
        return;
    }

    // If endpoint was stalled and there is now space make it valid
#ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
    uint16_t max_payload_length = PIOS_USB_BOARD_HID_DATA_LENGTH - 1;
#else
    uint16_t max_payload_length = PIOS_USB_BOARD_HID_DATA_LENGTH - 2;
#endif

    PIOS_IRQ_Disable();
    if ((GetEPRxStatus(usb_hid_dev->cfg->data_rx_ep) != EP_RX_VALID) &&
        (rx_bytes_avail >= max_payload_length)) {
        SetEPRxStatus(usb_hid_dev->cfg->data_rx_ep, EP_RX_VALID);
    }
    PIOS_IRQ_Enable();
}

static void PIOS_USB_HID_TxStart(uint32_t usbhid_id, __attribute__((unused)) uint16_t tx_bytes_avail)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)usbhid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    if (!PIOS_USB_CheckAvailable(usb_hid_dev->lower_id)) {
        return;
    }

    if (GetEPTxStatus(usb_hid_dev->cfg->data_tx_ep) == EP_TX_VALID) {
        /* Endpoint is already transmitting */
        return;
    }

    PIOS_USB_HID_SendReport(usb_hid_dev);
}

static void PIOS_USB_HID_RegisterRxCallback(uint32_t usbhid_id, pios_com_callback rx_in_cb, uint32_t context)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)usbhid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    /*
     * Order is important in these assignments since ISR uses _cb
     * field to determine if it's ok to dereference _cb and _context
     */
    usb_hid_dev->rx_in_context = context;
    usb_hid_dev->rx_in_cb = rx_in_cb;
}

static void PIOS_USB_HID_RegisterTxCallback(uint32_t usbhid_id, pios_com_callback tx_out_cb, uint32_t context)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)usbhid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    /*
     * Order is important in these assignments since ISR uses _cb
     * field to determine if it's ok to dereference _cb and _context
     */
    usb_hid_dev->tx_out_context = context;
    usb_hid_dev->tx_out_cb = tx_out_cb;
}

/**
 * @brief Callback used to indicate a transmission from device INto host completed
 * Checks if any data remains, pads it into HID packet and sends.
 */
static void PIOS_USB_HID_EP_IN_Callback(void)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)pios_usb_hid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    if (!PIOS_USB_CheckAvailable(usb_hid_dev->lower_id)) {
        return;
    }

    PIOS_USB_HID_SendReport(usb_hid_dev);
}

/**
 * EP1 OUT Callback Routine
 */
static void PIOS_USB_HID_EP_OUT_Callback(void)
{
    struct pios_usb_hid_dev *usb_hid_dev = (struct pios_usb_hid_dev *)pios_usb_hid_id;

    bool valid = PIOS_USB_HID_validate(usb_hid_dev);

    PIOS_Assert(valid);

    uint32_t DataLength;

    /* Read received data (63 bytes) */
    /* Get the number of received data on the selected Endpoint */
    DataLength = GetEPRxCount(usb_hid_dev->cfg->data_rx_ep);
    if (DataLength > sizeof(usb_hid_dev->rx_packet_buffer)) {
        DataLength = sizeof(usb_hid_dev->rx_packet_buffer);
    }

    /* Use the memory interface function to read from the selected endpoint */
    PMAToUserBufferCopy((uint8_t *)usb_hid_dev->rx_packet_buffer,
                        GetEPRxAddr(usb_hid_dev->cfg->data_rx_ep),
                        DataLength);

    if (!usb_hid_dev->rx_in_cb) {
        /* No Rx call back registered, disable the receiver */
        SetEPRxStatus(usb_hid_dev->cfg->data_rx_ep, EP_RX_NAK);
        return;
    }

    /* The first byte is report ID (not checked), the second byte is the valid data length */
    uint16_t headroom;
    bool need_yield = false;
#ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
    (usb_hid_dev->rx_in_cb)(usb_hid_dev->rx_in_context,
                            &usb_hid_dev->rx_packet_buffer[1],
                            sizeof(usb_hid_dev->rx_packet_buffer) - 1,
                            &headroom,
                            &need_yield);
#else
    (usb_hid_dev->rx_in_cb)(usb_hid_dev->rx_in_context,
                            &usb_hid_dev->rx_packet_buffer[2],
                            usb_hid_dev->rx_packet_buffer[1],
                            &headroom,
                            &need_yield);
#endif

#ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
    uint16_t max_payload_length = PIOS_USB_BOARD_HID_DATA_LENGTH - 1;
#else
    uint16_t max_payload_length = PIOS_USB_BOARD_HID_DATA_LENGTH - 2;
#endif

    if (headroom >= max_payload_length) {
        /* We have room for a maximum length message */
        SetEPRxStatus(usb_hid_dev->cfg->data_rx_ep, EP_RX_VALID);
    } else {
        /* Not enough room left for a message, apply backpressure */
        SetEPRxStatus(usb_hid_dev->cfg->data_rx_ep, EP_RX_NAK);
    }

#ifdef PIOS_INCLUDE_FREERTOS
    if (need_yield) {
        vPortYield();
    }
#endif /* PIOS_INCLUDE_FREERTOS */
}

#endif /* PIOS_INCLUDE_USB_HID */
